. Since the installation of the Gatan camera, we have focussed on consolidating and capitalizing on the work that was accomplished by Jim Kremer before his departure, and on providing an efficient interface for users to obtain tilt series with the camera. The microscope control system consists of an older PC running DOS and hosting a set of Keithly Metrabyte digital and analog input/output boards. These boards receive a host of signals from the microscope and are intended to drive various deflectors and lenses. The latter functions have not yet been implemented; currently the system is capable of controlling only stage position and tilt. A pair of motors has been installed on the microscope to drive stage translation. The basic step size is about 40 nm, but stage control is not as fine as this because the stage mechanism has backlash and cross-talk between the two axes of movement. After programming the control computer to compensate for these limitations, the accuracy of movement is on the order of 200 nm, which should be adequate for montaging. The camera control computer is a Macintosh PowerPC running MacOS. This computer communicates with the microscope control system via a serial interface. A program has been written to allow the user to control both the camera and the microscope, and to capture images, compare one image with another, and save images to a file. The file is in the MRC format, directly usable by the rest of our software running under Unix. This program was designed to overcome some of the shortcomings of Gatan's Digital Micrograph camera control program for the repetitive tasks of obtaining images from serial tilts or serial sections. We are currently exploring the possibility of using software from other laboratories (Bridget Carragher's group for remote microscope control, Koster and Agard's software for automated tomography) when more sophisticated control of the microscope becomes available.